Oliver Heaviside (1850 - 1925, England)

Caught scarlet fever when he was a young child and this affected his hearing.
At age 16 he left school. He taught himself Morse code and electricity. He was helped by his uncle Charles Wheatstone (after whom the Wheatstone bridge* was named).
Heaviside introduced operational calculus to enable him to solve the ordinary DEs which came out of the theory of electrical circuits. He replaced the differential operator ^d/_dx by a variable p transforming a differential equation into an algebraic equation. The solution of the algebraic equation could be transformed back using conversion tables to give the solution of the original differential equation.
Had the idea for an induction coil to increase induction, but it was patented in 1904 in the United States by AT&T.
His nails were always exquisitely manicured, and painted a glistening cherry pink...(!)